Preparation of Activated Carbon-Reinforced Composite Beads Based on MnO2/MCM-41@Fe3O4 and Calcium Alginate for Efficient Removal of Tetracycline in Aqueous Solutions

Zhigong Zheng; Ronghui Shi; Xiaoping Zhang; Yonghao Ni; Hui Zhang

doi:10.3390/polym16081115

Preparation of Activated Carbon-Reinforced Composite Beads Based on MnO₂/MCM-41@Fe₃O₄ and Calcium Alginate for Efficient Removal of Tetracycline in Aqueous Solutions

Polymers (Basel). 2024 Apr 16;16(8):1115. doi: 10.3390/polym16081115.

Authors

Zhigong Zheng^{1

2}, Ronghui Shi², Xiaoping Zhang², Yonghao Ni³, Hui Zhang¹

Affiliations

¹ College of Material Engineering, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
² School of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou 350118, China.
³ Department of Chemical Engineering, University of New Brunswick, Fredericton, NB E3B 5A3, Canada.

Abstract

Tetracycline (TC) is a common antibiotic; when untreated TC enters the environment, it will cause a negative impact on the human body through the food chain. In the present study, MnO₂/MCM-41@Fe₃O₄ (FeMnMCM) prepared using a hydrothermal and redox method and Camellia oleifera shell-activated carbon (COFAC) prepared through alkali activation were encapsulated using alginate (ALG) and calcium chloride as a cross-linking matrix to give the composite beads COFAC-FeMnMCM-ALG. The resultant COFAC-FeMnMCM-ALG composite beads were then carefully characterized, showing a high immobilization of MnO₂/MCM-41@Fe₃O₄, with porous COFAC as an effective bioadsorbent for enriching the pollutants in the treated samples. These bead catalysts were subsequently applied to the oxidative degradation of TC in a Fenton oxidation system. Several parameters affecting the degradation were investigated, including the H₂O₂ concentration, catalyst dosage, initial TC concentration, and temperature. A very high catalytic activity towards the degradation of TC was demonstrated. The electron paramagnetic resonance (EPR) and quenching results showed that ·OH and ·O₂^- were generated in the system, with ·OH as the main radical species. In addition, the COFAC-FeMnMCM-ALG catalyst exhibited excellent recyclability/reusability. We conclude that the as-prepared COFAC-FeMnMCM-ALG composite beads, which integrate MnO₂ and Fe₃O₄ with bioadsorbents, provide a new idea for the design of catalysts for advanced oxidation processes (AOPs) and have great potential in the Fenton oxidation system to degrade toxic pollutants.

Keywords: COFAC; MnO2/MCM-41@Fe3O4; alginate; catalyst; composite beads; tetracycline.

Grants and funding

This research was funded by the Natural Science Foundation of the Fujian Province (Grant Nos. 2023J01936 and 2023J01931), the National Natural Science Foundation of China (Grant No. 52070043), and the Fuzhou Major Science and Technology Projects (Grant No. 2023-ZD-008).